High flow therapy device utilizing a non-sealing respiratory interface and related methods

ABSTRACT

A high flow therapy system for delivering heated and humidified respiratory gas to an airway of a patient includes a respiratory gas flow pathway for delivering the respiratory gas to the airway of the patient by way of a non-sealing respiratory interface; wherein flow rate of the respiratory gas is controlled by a microprocessor, a mixing area for mixing a first gas and a second gas in the respiratory gas flow pathway, a humidification area downstream of the mixing area and configured for humidifying respiratory gas in the respiratory gas flow pathway, and a heated delivery conduit for minimizing condensation of humidified respiratory gas.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 13/717,442, filed on Dec. 17, 2012, which is acontinuation application of U.S. patent application Ser. No. 11/638,981,filed on Dec. 14, 2006, now U.S. Pat. No. 8,333,194, which is acontinuation-in-part application of U.S. patent application Ser. No.11/520,490, filed on Sep. 12, 2006, which claims the benefit of U.S.Provisional Patent Application Ser. No. 60/716,776, filed Sep. 12, 2005.The present application also claims the benefit and priority of U.S.Provisional Patent Application Ser. No. 60/750,063, filed on Dec. 14,2005; U.S. Provisional Patent Application Ser. No. 60/792,711, filed onApr. 18, 2006; and U.S. Provisional Patent Application Ser. No.60/852,851, filed on Oct. 18, 2006. The entire contents of each of theseapplications are hereby incorporated by reference herein.

BACKGROUND

Respiratory interfaces, e.g., nasal cannulas are used to deliverrespiratory gases for therapeutic effect, including oxygen therapy,treatment for sleep apnea, and respiratory support. Small nasal cannulasare commonly used for delivery of low volumes of oxygen. Sealing nasalcannulas, such as the cannulas disclosed in U.S. Pat. No. 6,595,215 toWood, are used for the treatment of sleep apnea. However, treatment withcertain types of nasal cannulas may be limited by the lack ofinformation available on important treatment parameters. Theseparameters include information regarding the gases within the user'supper airway, such as pressure, flow rate, and carbon dioxide build up.These and other data may be useful in judging the efficacy of treatmentas well as for controlling and monitoring treatment.

In addition, prior art nasal cannula designs (especially those designedfor neonatal oxygen therapy) may undesirably create a seal with theuser's nares, which may have detrimental effects on the user's health.

Oxygen (O₂) therapy is often used to assist and supplement patients whohave respiratory impairments that respond to supplemental oxygen forrecovery, healing and also to sustain daily activity.

Nasal cannulas are generally used during oxygen therapy. This method oftherapy typically provides an air/gas mixture including about 24% toabout 35% O₂ at flow rates of 1-6 liters per minute (L/min). At aroundtwo liters per minute, the patient will have a FiO₂ (percent oxygen inthe inhaled O₂/air mixture) of about 28% oxygen. This rate may beincrease somewhat to about 8 L/min if the gas is passed through ahumidifier at room temperature via a nasal interface into the patient'snose. This is generally adequate for many people whose conditionresponds to about 35-40% inhaled O₂ (FiO₂), but for higherconcentrations of O₂, higher flow rates are generally needed.

When a higher FiO₂ is needed, one cannot simply increase the flow rate.This is true because breathing 100% O₂ at room temperature via a nasalcannula is irritating to the nasal passage and is generally nottolerated above about 7-8 L/min. Simply increasing the flow rate mayalso provoke bronchospasm.

To administer FiO₂ of about 40% to about 100%, non-re-breathing masks(or sealed masks) are used at higher flows. The mask seals on the faceand has a reservoir bag to collect the flow of oxygen during theexhalation phase and utilize one-way directional valves to directexhalation out into the room and inhalation from the oxygen reservoirbag. This method is mostly employed in emergency situations and isgenerally not tolerated well for extended therapy.

High flow nasal airway respiratory support (“high flow therapy” or“HFT”) is administered through a nasal cannula into an “open” nasalairway. The airway pressures are generally lower than ContinuousPositive Airway Pressure (CPAP) and Bi-level Positive Airway Pressure(BiPAP) and are not monitored or controlled. The effects of such highflow therapies are reported as therapeutic and embraced by someclinicians while questioned by others because it involves unknownfactors and arbitrary administration techniques. In such procedures, thepressures generated in the patients' airways are typically variable,affected by cannula size, nare size, flow rate, and breathing rate, forinstance. It is generally known that airway pressures affect oxygensaturation, thus these variables are enough to keep many physicians fromutilizing HFT.

SUMMARY

The present disclosure relates to a high flow therapy system fordelivering heated and humidified respiratory gas to an airway of apatient includes a respiratory gas flow pathway for delivering therespiratory gas to the airway of the patient by way of a non-sealingrespiratory interface; wherein flow rate of the respiratory gas iscontrolled by a microprocessor, a mixing area for mixing a first gas anda second gas in the respiratory gas flow pathway, a humidification areadownstream of the mixing area and configured for humidifying respiratorygas in the respiratory gas flow pathway, and a heated delivery conduitfor minimizing condensation of humidified respiratory gas. Anotheraspect of this embodiment provides for at least one of respiration rate,tidal volume and minute volume are calculated by the microprocessorusing data from the airway pressure sensor.

The present disclosure also relates to a method of supplying a patientwith gas. The method includes providing a high flow therapy deviceincluding a microprocessor, a heating element disposed in electricalcommunication with the microprocessor and capable of heating a liquid tocreate a gas, a non-sealing respiratory interface configured to deliverthe gas to a patient and a sensor disposed in electrical communicationwith the microprocessor and configured to measure pressure in the upperairway of the patient. This method also includes heating the gas anddelivering the gas to a patient.

The present disclosure also relates to a high flow therapy system fordelivering pressurized, heated and humidified respiratory gas to anairway of a patient includes a respiratory gas flow pathway fordelivering the pressurized respiratory gas to the airway of the patientby way of a non-sealing respiratory interface; where flow rate of thepressurized respiratory gas is controlled by a microprocessor, a mixingarea for mixing oxygen and air in the respiratory gas flow pathway, ahumidification area for humidifying respiratory gas in the respiratorygas flow pathway, a heated delivery conduit for minimizing condensationof humidified respiratory gas and a pressure pathway for monitoringpressure of the airway of the patient and communicating the monitoredpressure to the microprocessor, where the system is configured todetermine the respiratory phase of the patient.

The present disclosure also relates to a method of supplying a patientwith gas. The method including providing a high flow therapy device,heating a gas and delivering the gas to a patient. The high flow therapydevice of this method includes a heating element, a non-sealingrespiratory interface, a blower, an air inlet port and an air filter.The heating element is capable of heating a liquid to create a gas. Thenon-sealing respiratory interface is configured to deliver the gas to apatient. The blower is dispose din mechanical cooperation with thenon-sealing respiratory interface and is capable of advancing the gas atleast partially through the non-sealing respiratory interface. The airinlet port is configured to enable ambient air to flow towards to theblower. The air filter is disposed in mechanical cooperation with theair inlet port and is configured to remove particulates from the ambientair.

The present disclosure also relates to a method of treating a patientfor an ailment such as a headache, upper airway resistance syndrome,obstructive sleep apnea, hypopnea and snoring. The method includesproviding a high flow therapy device, heating a gas and delivering thegas to a patient. The high flow therapy device includes a heatingelement capable of heating a liquid to create a gas and a non-sealingrespiratory interface configured to deliver the gas to a patient.

The present disclosure also relates to a method of deliveringrespiratory gas to a patient. The method includes providing a high flowtherapy device, monitoring the respiratory phase of the patient andpressurizing the gas. The high flow therapy device of this methodincludes a heating element capable of heating a liquid to create a gas,a non-sealing respiratory interface configured to deliver the gas to apatient, and a sensor configured to measure pressure in the upper airwayof the patient.

The present disclosure also relates to a high flow therapy deviceincluding a microprocessor, a heating element, a non-sealing respiratoryinterface, a sensor and a mouthpiece. The heating element is disposed inelectrical communication with the microprocessor and is capable ofheating a liquid to create a gas. The non-sealing respiratory interfaceis configured to deliver the gas to a patient. The sensor is disposed inelectrical communication with the microprocessor and is configured tomeasure pressure in an upper airway of the patient. The mouthpiece isdisposed in mechanical cooperation with the sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the accompanying drawing figures, whichare not necessarily drawn to scale.

FIG. 1 is a perspective view of a nasal cannula according to aparticular embodiment of the invention.

FIG. 2 is a perspective view of a nasal cannula according to a furtherembodiment of the invention.

FIG. 3 is a perspective view of a nasal cannula according to anotherembodiment of the invention.

FIG. 4 is a perspective view of a nasal cannula according to yet anotherembodiment of the invention.

FIG. 5 is a front perspective view of a nasal cannula according to afurther embodiment of the invention.

FIG. 6 depicts a cross section of a nasal insert of a nasal cannulaaccording to a particular embodiment of the invention.

FIG. 7 depicts a cross section of a nasal insert of a nasal cannulaaccording to a further embodiment of the invention.

FIG. 8A is a front perspective view of a nasal cannula according toanother embodiment of the invention.

FIG. 8B is a rear perspective view of the nasal cannula shown in FIG.8A.

FIG. 8C is a perspective cross-sectional view of the nasal cannula shownin FIG. 8A.

FIG. 9 is a perspective view of a nasal cannula according to a furtherembodiment of the invention.

FIG. 10 is a perspective view of a nasal cannula according to anotherembodiment of the invention.

FIG. 11 is a perspective view of a nasal cannula according to a furtherembodiment of the invention.

FIG. 12 is a perspective view of a nasal cannula according to yetanother embodiment of the invention.

FIG. 13 illustrates an embodiment of a nasal cannula in use on apatient, according to one embodiment of the invention.

FIG. 14 illustrates another embodiment of a nasal cannula in use on apatient, according to a further embodiment of the invention.

FIG. 15 illustrates a perspective view of a high flow therapy device inaccordance with an embodiment of the present disclosure.

FIG. 16 illustrates a perspective view of the high flow therapy deviceof FIG. 15 showing internal components, in accordance with an embodimentof the present disclosure.

FIG. 17 illustrates a schematic view of the high flow therapy device ofFIGS. 15 and 16 with a nasal interface and a patient in accordance withan embodiment of the present disclosure.

FIG. 18 illustrates a high flow therapy device including a nasalinterface and a conduit in accordance with an embodiment of the presentdisclosure.

FIGS. 19 and 20 illustrate an enlarged view of a patient's upper airwayand a nasal interface in accordance with two embodiments of the presentdisclosure.

FIG. 21 illustrates an example of a screen shot of a user interface ofthe high flow therapy device of FIGS. 15-17 in accordance with anembodiment of the present disclosure.

FIGS. 22 and 23 illustrate examples of a non-sealing respiratoryinterface in the form of a mouthpiece in accordance with embodiments ofthe present disclosure.

FIG. 24 illustrates a mouthpiece of FIG. 22 or 23 in use on a patient inaccordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The present inventions now will be described with reference to theaccompanying drawings, in which some, but not all embodiments of theinventions are shown. Indeed, these inventions may be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will satisfy applicable legal requirements. Likenumbers refer to like elements throughout. For example, elements 130,230, 330, 430, 530, 830, and 930 are all nozzles according to variousembodiments of the invention.

Overview of Functionality

Nasal cannula according to various embodiments of the invention may beconfigured to deliver high-flow therapeutic gases to a patient's upperairway through the patient's nose. Such gases may include, for example,air, humidity, oxygen, therapeutic gases or a mixture of these, and maybe heated or unheated. In particular embodiments of the invention, thecannula may be useful for CPAP (continuous positive airway pressure)applications, which may be useful in the treatment of sleep apnea and inproviding respiratory support to patients (e.g., after abdominalsurgery), to alleviate snoring, or for other therapeutic uses.

Nasal cannula according to particular embodiments of the inventioninclude (or are adapted to facilitate the positioning of) one or moresensors adjacent or within one or more of the cannula's nasal inserts.Accordingly, the nasal cannula may be configured so that at least aportion of one or more sensors is in place in one or both of a user'snares when the nasal cannula is operably worn by the user. This may beparticularly helpful in evaluating the environment of the internalportion of the user's nose and/or the user's upper airway. As describedin greater detail below, in various embodiments of the invention, thecannula is adapted so that it will not create a seal with the patient'snares when the cannula is in use.

Nasal cannula according to other embodiments of the invention includenozzles. A nozzle may be a nasal insert that is inserted into the user'snares. Other nozzles are adapted to remain outside of a user's nareswhile the cannula is in use. Accordingly, the nozzles avoid sealing withthe patient's nares while the cannula is in use. In some embodiments,the nasal cannula include elongate extensions that are inserted into theuser's nares to detect pressure in one or both nares.

In certain embodiments of the invention, sensors are provided adjacentor within both of the nasal cannula's nozzles. In various otherembodiments, sensors are provided adjacent or within one or moreelongate extensions that extend into the user's nares. In variousembodiments, elongate extensions may be used in conjunction with nasalinserts or with nozzles. The use of sensors may be useful, for example,in monitoring environmental changes from one of the user's nares to theother. This information may be helpful, for example, in determining whenthe dominant flow of air changes from one of the user's nares to theother, which may affect the desired flow characteristics of therapy.Accordingly, data from each nare may provide information that may beuseful in establishing or modifying the user's treatment regimen.Further, multiple sensors may be used in various embodiments.

Overview of Exemplary Cannula Structures

A cannula 100 according to one embodiment of the invention is shown inFIG. 1. As may be understood from this figure, in this embodiment, thecannula 100 includes a hollow, elongated tubular base 105 that includesa central portion 110, a first end portion 115, and a second end portion120. The first and second end portions 115, 120 may be angled relativeto the central portion 110 as shown in FIG. 1.

In various embodiments of the invention, the cannula 100 includes afirst tubing inlet 117 adjacent the outer end of the first end portion115, and a second tubing inlet 122 adjacent the second end portion 120(in other embodiments, the cannula may include only one such inlet). Thecannula 100 further comprises a pair of hollow, elongated, tubularnozzles (e.g., nasal catheters) 125, 130 that extend outwardly from thenasal cannula's base portion 105 and that are in gaseous communicationwith the base portion's interior. In various embodiments, the respectivecentral axes of the nozzles 125, 130 are substantially parallel to eachother, and are substantially perpendicular to the central axis of thecentral portion 110 of the nasal cannula's base portion 105.

In particular embodiments of the invention, the cannula defines at leastone conduit that is adapted to guide at least one sensor so that thesensor is introduced adjacent or into the interior of the cannula sothat, when the cannula is being operably worn by a user, the environmentbeing monitored by the at least one sensor reflects that of the internalportion of the user's nose and/or the user's upper airway. In variousembodiments of the invention, a user may temporarily insert the at leastone sensor into or through the conduit to determine correct settings forthe cannula system, and then may remove the sensor after the correctsettings have been achieved. In other embodiments, the at least onesensor may be left in place within the conduit for the purpose ofmonitoring data within (or adjacent) the cannula over time (e.g., forpurposes of controlling the user's therapy regimen). In a furtherembodiment, the at least one sensor may be positioned adjacent an outletof the conduit.

The at least one sensor may be connected (e.g., via electrical wires) toa computer and/or a microprocessor that is controlling the flow ofrespiratory gases into the cannula. The computer may use informationreceived from the at least one sensor to control this flow of gas and/orother properties of the system, or may issue an alarm if the informationsatisfies pre-determined criteria (e.g., if the information indicatespotentially dangerous conditions within the patient's airway or if thesystem fails to operate correctly).

As may be understood from FIGS. 8A-8C, in a particular embodiment of theinvention, at least one of the cannula's conduits 850 is defined by, andextends within, a side wall of the cannula 800. Alternatively, theconduit may be disposed within an interior passage defined by thecannula. For example, one or more of the conduits may be defined by atube that is attached immediately adjacent an interior surface of thecannula (e.g., adjacent an interior surface of the cannula's baseportion, or an interior surface of one of the cannula's nozzles). Thecannula's conduits are preferably adapted for: (1) receiving a flow ofgas at one or more inlets that are in communication with the conduit,and (2) guiding this flow of gas to an outlet in the cannula. In variousembodiments, one or more of the inlets is defined within an exteriorportion of one of the cannula's nozzles.

As may be understood from FIG. 1, in various embodiments of theinvention, each of the cannula's conduit outlets 136, 141 is located atthe end of a respective elongate, substantially tubular, outlet member135, 140. For example, in the embodiment shown in FIG. 1, the cannula100 includes a first outlet member 135 that is substantially parallel tothe cannula's first nozzle 125. In this embodiment, the first outletmember 135 and the first nozzle 125 may be positioned on opposite sidesof the nasal cannula's base portion 105 as shown in FIG. 1. Similarly,in a particular embodiment of the invention, the cannula 100 includes asecond outlet member 140 that is substantially parallel to the cannula'ssecond nasal insert 130. The second outlet member 140 and second nozzle130 are also preferably positioned on opposite sides of the nasalcannula's base portion 105. Nozzles 125, 130 also may have nozzleoutlets 181, 182 respectively.

In various embodiments of the invention, a sensor (e.g., a pressure,temperature, or O₂ sensor) is provided in communication or adjacent atleast one of (and preferably each of) the cannula's outlets 136, 141 andis used to measure the properties of gas from that outlet 136, 141. In afurther embodiment of the invention, accessory tubing is used to connecteach outlet 135, 140 with at least one corresponding sensor (and/or atleast one external monitoring device) that may, for example, be spacedapart from the cannula 100.

In yet another embodiment of the invention, one or more sensors areprovided within the conduit, and used to measure the properties of gasaccessed through the conduit. In this embodiment, information from eachsensor may be relayed to a control system outside the cannula via, forexample, an electrical wire that extends from the sensor and through theoutlet 135, 140 of the conduit in which the sensor is disposed.

In alternative embodiments of the invention, each of the cannula'sconduits may extend: (1) from the conduit inlets 152, 154; (2) through,or adjacent, a side wall of one of the cannula's nozzles 125, 130; (3)through, or adjacent, a side wall of the cannula's base portion 105; and(4) to an outlet 135, 140 that is defined within, or disposed adjacent,the cannula's base portion 105. In one such embodiment, the conduitcomprises a substantially tubular portion that is disposed adjacent aninterior surface of the cannula's base portion.

As may be understood from FIG. 2, in certain embodiments of theinvention, the cannula 200 includes at least one sensor 245 that isintegrated into an exterior portion of the cannula 200 (e.g., within arecess 223 formed within an exterior surface of one of the cannula'snozzles 225, 230). In this embodiment, information from the sensor 245may be relayed to a control system outside the cannula 200 via anelectrical wire 246 that extends from the sensor 245, through a conduit,and out an outlet 235, 240 in the conduit. In various embodiments of theinvention, the conduit extends through or adjacent an interior portionof a sidewall of one of the cannula's nozzles 225, 230 and/or through oradjacent an interior portion of a sidewall of the cannula's base portion205. Nozzles 225, 230 also have nozzle outlets 281, 282 respectively.

In particular embodiments of the invention, at least one sensor 245 isfixedly attached to the cannula 100 so that it may not be easily removedby a user. Also, in particular embodiments, at least one sensor 245 isdetachably connected adjacent the cannula 100 so that the sensor 245 maybe easily detached from (and, in certain embodiments, reattached to) thecannula 100.

The cannula 1000 includes a hollow, elongated tubular base portion 1005that includes a central portion 1010, a first end portion 1015, and asecond end portion 1020. The first and second end portions 1015 and 1020may be angled relative to the central portion 1010, as shown in FIG. 10.In various embodiments of the invention, the cannula 1000 includes afirst tubing inlet 1017 adjacent the outer end of the first end portion1015, and a second tubing inlet 1022 adjacent the outer end of thesecond end portion 1020.

The cannula 1000 further comprises a pair of hollow, elongated, tubularnozzles (a first nozzle 1026 and a second nozzle 1031) that extendoutwardly from the nasal cannula's base portion 1005. In variousembodiments, the respective central axes of the nozzles 1026, 1031 aresubstantially parallel to each other and are substantially perpendicularto the central axis of the central portion 1010 of the nasal cannula'sbase portion 1005. In various embodiments, the nozzles 1026, 1031 definepassageways that are in gaseous communication with the interior of thecannula's base portion 1005. In particular embodiments of the invention,the first and second nozzles 1026, 1031 are adapted to be positionedoutside of a user's nares while the cannula is in use. In particularembodiments, the nozzles 1026, 1031 each define a respective nozzleoutlet. For example, the first nozzle 1026 defines a first nozzle outlet1083, and the second nozzle 1031 defines a second nozzle outlet 1084. Invarious embodiments, when the nasal cannula 1000 is operativelypositioned adjacent a user's nares, each of the nozzle's outlets 1083,1084 is positioned to direct a focused flow of gas into a correspondingone of the user's nares.

In alternative embodiments, such as the embodiment shown in FIG. 12, thenasal cannula 1200 may include a single nozzle 1227 that defines apassageway that is in gaseous communication with an interior portion ofthe cannula's base portion 1205. As described in greater detail below,in various embodiments, the nozzle 1227 extends outwardly from thecannula's base portion 1205 and has an oblong, or elliptical,cross-section. In this and other embodiments, the nozzle 1227 is shapedto deliver a focused flow of gas simultaneously into both of a user'snares when the cannula 1200 is in use.

In various embodiments, the nasal cannula includes one or more elongateextensions that are adapted for insertion into one or more of the user'snares. For example, returning to the embodiment shown in FIG. 10, thenasal cannula 1000 may include multiple elongate extensions (for examplea first elongate extension 1070 and a second elongate extension 1072)that are long enough to allow each of the elongate extensions 1070, 1702to be inserted into a respective one of the user's nares while the nasalcannula 1000 is in use. In embodiments, elongate extensions 1070, 1072may have conduit inlets 1052, 1053 respectively. In various embodiments,each of the elongate extensions 1070, 1072 may have a central axis thatruns substantially parallel to the central axis of a correspondingnozzle 1026, 1031. For example, as can be understood from FIG. 10, incertain embodiments, a first elongate extension 1070 has a central axisthat lies substantially parallel to and below the central axis of acorresponding first nozzle 1026, when the nasal cannula is operativelypositioned adjacent a user's nares. Similarly, in various embodiments, asecond elongate extension 1072 has a central axis that liessubstantially parallel to and below the central axis of a correspondingsecond nozzle 1031, when the nasal cannula 1000 is operativelypositioned adjacent a user's nares. In various other embodiments, theelongate extensions may lie within, and extend outwardly from, theircorresponding nozzles 1070, 1072.

As a further example, FIG. 12 illustrates an exemplary nasal cannula1200 having multiple elongate extensions (a first elongate extension1270 and a second elongate extension 1272), which both lie substantiallybeyond a single nozzle 1227 when the nasal cannula 1200 is in anoperative position adjacent the user's nose. In some embodiments, thecentral axes of the first and second elongate extensions 1270, 1272, maybe substantially parallel to the central axis of the nozzle 1227. Also,in various embodiments, one or both of the elongate extensions 1270,1272 may lie within the nozzle 1227. In this and other embodiments, adistal end of each of the elongate extensions 1270, 1272 may extendbeyond a distal end of the nozzle 1227. Elongate extensions 1270, 1272may have conduit inlets 1252, 1253 respectively, while nozzle 1227 has anozzle outlet 1281.

As described above, in certain embodiments of the invention, the nasalcannula includes one or more sensors that are adapted to measure gasdata (e.g., gas pressure) within the user's nares while the nasalcannula is in use. For example, the nasal cannula 1000 shown in FIG. 10may include a sensor positioned adjacent the distal end of one or bothof the first and second elongate extensions 1070, 1072. In variousembodiments, each elongate extension may be adapted to: (1) support asensor adjacent (e.g., at) the distal end of the elongate extension; and(2) support a wire that is simultaneously connected to the sensor and acontrol mechanism that is adapted to adjust the properties of gasflowing through the cannula 1000.

In other embodiments, the elongate extensions define conduits. Forexample, one or more sensor(s) may be positioned within the interior orexterior of the elongate extensions and information from the sensor(s)may be relayed to a control system via a wire extending through aconduit (for example, conduit 1023 of FIG. 10) or passages defined byeach of the elongate extensions. In one embodiment, as shown, forexample, in FIG. 10, the conduit 1023 is shaped similarly to the nasalcannula's base portion 1005, and lies substantially below the baseportion 1005 when the nasal cannula 1000 is operatively in use. Invarious embodiments, the conduit 1023 is positioned within the baseportion 1005 such that the first and second elongate extensions 1070,1072 lie within, and extend outwardly from, the respective first andsecond nozzles 1026, 1031.

In various embodiments, each elongate extension defines a respectivesensing conduit. For example, in certain embodiments, each sensingconduit is adapted to provide a passage that permits sensing or gaseouscommunication between a user's nares and a control system or otherdevice for measuring and adjusting the properties of the air. In thisand other embodiments, a sensor may be positioned at the control box tomeasure the properties (e.g., pressure) of air in the user's nares. Insome embodiments, the elongate extensions define a conduit that servesboth as an air passageway as well as a conduit for allowing a wire topass from a sensor positioned adjacent the distal tip of the elongateextension to the control system or other device.

Data Monitored by Sensors

In various embodiments of the invention, such as those described above,one or more sensors may be positioned to measure gas data within aninterior portion of one of the nasal cannula's conduits, or to measuregas data adjacent an exterior portion of the cannula. In suchembodiments, one or more sensors may be, for example, positionedadjacent an interior or exterior surface of the cannula. In certainembodiments of the invention, one or more of the cannula's sensors isadapted to monitor one or more of the following types of data within thecannula's conduits, or adjacent the cannula's exterior surface (e.g.,adjacent a side portion, or distal end of, one of the cannula'snozzles): (1) gas pressure; (2) gas flow rate; (3) carbon dioxidecontent; (4) temperature; (5) level; and/or (6) oxygen content.

Absolute vs. Relative Pressure Measurements

In various embodiments of the invention, the cannula may be configuredfor sensing absolute pressure within, or adjacent, a particular portionof the cannula. Similarly, in particular embodiments, the cannula may beconfigured to measure the difference between the pressures at twodifferent locations within the cannula. This may be done, for example,by providing two separate sensors (e.g., that are positioned indifferent locations within one of the cannula's conduits), or byproviding two physically distinct gas intake conduits, each of which isadapted for routing gas from a different location within the cannula.For example, in various embodiments of the invention shown in FIG. 1,the first conduit inlet 152 may be connected to a first conduit that isadapted for routing gas to a first sensor, and the second conduit inlet154 may be connected to a physically separate second conduit that isadapted for routing gas to a second pressure sensor. Information fromthe first and second sensors may then be used to calculate thedifference in pressure between the first and second inlets 152, 154.Alternatively, a differential pressure sensor may be used.

Suitable Sensors

Suitable sensors for use with various embodiments of the inventioninclude electronic and optical sensors. For example, suitable sensorsmay include: (1) Disposable MEM Piezoelectric sensors (e.g., from SilexMicrosensors); (2) light-based sensors such as a McCaul O₂ sensor—seeU.S. Pat. No. 6,150,661 to McCaul; and (3) Micro-pressure sensors, suchas those currently available from Honeywell.

Non-Sealing Feature

As shown in FIG. 4, in various embodiments of the invention, one or moreof the nasal cannula's 400 nozzles 425, 430 includes one or morerecesses 423 (e.g., grooves, semicircular recesses, or otherindentations or conduits) that extend along a length of the nozzle'sexterior surface. As may be understood from this figure, in variousembodiments of the invention, at least one of these recesses 423 is anelongate groove that extends from adjacent a distal surface of thenozzle 425, 430 and past the midpoint between: (1) the nozzle's distaltip and (2) the portion of the nozzle 425, 430 that is immediatelyadjacent the nasal cannula's base portion 405. As may also be understoodfrom this figure, in various embodiments of the invention, each groove423 extends substantially parallel to the central axis of its respectivenozzle 425, 430. Nozzles 425, 430 also have nozzle outlets 481, 482respectively. As shown in FIG. 3, in various embodiments of theinvention, one or more of the nasal cannula's 300 nozzles 325, 330includes one or more recesses 323 that extend along a portion of lengthof the nozzle's exterior surface. As may be understood from this figure,in various embodiments of the invention, at least one of these recesses323 is an elongate groove that extends from adjacent a distal surface ofthe nozzle 325, 330 between: (1) the nozzle's distal tip and (2) theportion of the nozzle 325, 330 that is immediately adjacent the nasalcannula's base portion 305. As may also be understood from this figure,in various embodiments of the invention, each groove 323 extendssubstantially parallel to the central axis of its respective nozzle 325,330. Nozzles 325, 330 also have nozzle outlets 381, 382 respectively.

In particular embodiments of the invention, such as the embodiment shownin FIG. 4, at least one of the nasal cannula's nozzles 425, 430 isconfigured so that when the nozzles 425, 430 are operatively positionedwithin a user's nares, the nozzles do not form an airtight seal with theuser's nares. This may be due, for example, to the ability of air toflow adjacent the user's nare through recesses 423 in the nozzles 425,430 when the user is wearing the nasal cannula.

FIGS. 5-8 depict additional embodiments of the invention that areconfigured so that when the cannula's nasal inserts are operativelypositioned adjacent (e.g., partially within) the user's nares, the nasalinserts do not form a seal with the user's nares. For example, in theembodiment shown in FIG. 5, at least one (and preferably both) of thecannula's nasal inserts 525, 530 comprise an inlet 555 (which may, forexample, be substantially tubular), and one or more flange portions 560,561 that are adapted to maintain a physical separation between anexterior side surface of the inlet 555 and a user's nare when the nasalinsert 525, 530 is inserted into the user's nare.

For example, in the embodiment of the invention shown in FIG. 5, each ofthe cannula's nozzles 525, 530 includes a substantially tubular nozzlebody portion 555 and a pair of co-facing, elongated flanges 560, 561that each have a substantially C-shaped cross section. In thisembodiment, these C-shaped flanges 560, 561 cooperate with a portion ofthe exterior of the nozzle body portion 555 to form a substantiallyU-shaped channel (which is one example of a “nasal lumen”) through whichambient air may flow to and/or from a user's nasal passages when thecannula 500 is operatively in place within the user's nares. In thisembodiment, when the nozzles 525, 530 are properly in place within theuser's nares, respiratory gas is free to flow into the-user's nosethrough the nozzle body portion 555, and ambient air is free to flowinto and out of the user's nose through a passage defined by: (1) theflanges 560, 561; (2) the exterior side surface of the nozzle bodyportion 555 that extends between the flanges 560, 561; and (3) aninterior portion of the user's nose. In various embodiments, air mayflow to and/or from a user's nose through this passage when the cannula500 is operatively in place within the user's nares. A pathway (e.g., asemicircular pathway) may be provided adjacent the interior end of thisU-shaped channel, which may act as a passageway for gas exhaled andinhaled through the U-shaped channel. In embodiments, nozzles 525, 530may have conduit inlets 552, 554, and cannula 500 may have conduitoutlets 535, 540.

The general embodiment shown in FIG. 5 may have many differentstructural configurations. For example, as shown in FIG. 6, whichdepicts a cross section of a nozzle according to a particular embodimentof the invention, the respiratory gas passageways of the cannula'snozzles 655 may be in the form of a tube having an irregular crosssection (e.g., a substantially pie-piece-shaped cross section) ratherthan a circular cross section. Alternatively, as may be understood fromFIG. 7, the respiratory gas passageways of the cannula's nozzles 755 maybe in the form of a tube having a substantially half-circular crosssection rather than a circular cross section.

Similarly, as may be understood from FIGS. 6 and 7, the shape and sizeof the cannula's flanges may vary from embodiment to embodiment. Forexample, in the embodiment shown in FIG. 6, each of the flanges 660, 661has a relatively short, substantially C-shaped cross section and thedistal ends of flanges 660, 661 are spaced apart from each other to forma gap. As shown in FIG. 7, in other embodiments, each of the flanges760, 761 may have a relatively long, substantially C-shaped crosssection and the distal ends of the flanges 760, 761 may be positionedimmediately adjacent each other.

As may be understood from FIG. 7, in various embodiments of theinvention, a separation 763 (e.g., a slit, such as an angular slit) isprovided between the flanges 760, 761. This may allow the flanges 760,761 to move relative to each other and to thereby conform to the nare inwhich the nozzle is inserted. In other embodiments, the cross section ofthe nozzles is substantially as that shown in FIG. 7, except that noseparation 763 is provided within the semi-circular flange portion.Accordingly, in this embodiment of the invention, a substantiallysemi-circular portion of the exterior of the air passageway cooperateswith a substantially semi-circular portion of the flange portion to forman exterior having a contiguous, substantially circular cross section.One such embodiment is shown in FIGS. 8A-8C.

As may be understood from FIGS. 8A-8C, in this embodiment, when thecannula 800 is in use, respiratory gas may flow into the user's nosethrough inspiratory passageways 881 that extend through each of thecannula's nozzles 825, 830. Inspiratory passageways 881 are in gaseouscommunication with the interior of base portion 805 as shown in FIG. 8C.An expiratory passageway_885 of substantially semi-circular crosssection extends between the distal end of each nozzle 825, 830 to asubstantially semicircular expiratory passageway outlet 865 definedwithin the cannula's base portion 805. In various embodiments, when thecannula 800 is in use, the user may exhale or both inhale and exhale gasthrough this expiratory passageway 885. As previously mentioned, thiscannula embodiment does not form a seal within the user's nares due tothe expiratory passageways 885, even if the nozzles 825, 830 tightly fitwithin the nares. In further embodiments, nozzles 825, 830 may haverecesses 823.

In certain embodiments, as discussed above, a conduit 850 is provided ineach of the cannula's nozzles 825, 830 (see FIG. 8C) and may haveconduit inlets 852, 854. Each of these conduits 850 may be adapted tofacilitate measuring gas data by: (1) receiving gas from the interior ofa corresponding expiratory passageway 885 and/or from adjacent theexterior of one of the cannula's nozzles 825, 830, and/or (2) guidingthe gas out of a corresponding conduit outlet 835, 840 in the cannula800. As discussed above, one or more sensors may be disposed within, oradjacent, the conduit 850 and used to assess one or more attributes ofgas flowing through or adjacent the conduit 850.

It should be understood that the embodiments of the invention shown inFIGS. 4-8 and related embodiments may have utility with or without theuse of sensors or sensor conduits. It should also be understood that thevarious nozzles may be configured to be disposed in any appropriateorientation within the user's nares when the cannula is operablypositioned within the user's nares. For example, in one embodiment ofthe invention, the cannula may be positioned so that the cannula's nasallumen is immediately adjacent, or so that it faces anterior-laterallyaway from, the user's nasal spine.

Turning to yet another embodiment of the invention, as shown in FIG. 9,the cannula 900 may be adapted so that a conduit inlet 970, 972 for atleast one sensor (or the sensing conduit itself) is maintained adjacent,and spaced a pre-determined distance apart from, the distal end of arespective nozzle 925, 930. In this embodiment, the sensor (or conduitinlet) may be spaced apart from the rest of the nasal cannula 900adjacent one of the nozzle outlet openings. In embodiments, cannula 900may have conduit outlets 935, 940.

As may be understood from FIG. 10, in various embodiments, the first andsecond nozzles 1026, 1031 of the nasal cannula are configured to remainoutside of the user's nares while the cannula is in use. For example,the nozzles may be of a length such that, when the cannula is in use,the distal ends of the nozzles 1026, 1031 lie adjacent, but outside, theuser's nares. By preventing insertion of the nozzles 1026, 1031 into thenares, sealing of the nares can be avoided. As may be understood fromFIG. 13, in various embodiments, when the nasal cannula is in anoperative position adjacent the user's nares, an outlet portion (anddistal end) of each nozzle 1326, 1331 is spaced apart from, andsubstantially in-line (e.g., substantially co-axial) with, acorresponding one of the patient's nares. In various embodiments, whenthe nasal cannula is operatively in use, the outlet of each nozzle isspaced apart from the patient's nares and each nozzle is positioned todirect a focused flow of gas into a particular respective one of theuser's nares.

Referring to FIG. 11, cannula 1100 includes a hollow, elongated tubularbase portion 1105 that includes a central portion 1110, a first endportion 1115, and a second end portion 1120. The first and second endportions 1115, 1120 may be angled relative to the central portion 1110,as shown in FIG. 11. In various embodiments of the invention, thecannula 1100 includes a first tubing inlet 1117 adjacent the outer endof the first end portion 1115, and a second tubing inlet 1122 adjacentthe outer end of the second end portion 1020. As may be understood fromFIG. 11, in particular embodiments, a stop 1190 may extend outwardlyfrom the base portion 1105 of the nasal cannula 1100. In someembodiments, the stop 1190 lies in between the first and second nozzles1126, 1131 and defines a central axis that runs substantially parallelto the respective central axes of the nozzles 1126, 1131. The stop 1190,in some embodiments, may extend outwardly from the nasal cannula's baseportion 1105 a length greater than that of the nozzles 1126, 1131. Inthis manner, the stop 1190 prevents the nozzles 1126, 1131 from beinginserted into the user's nares when the nasal cannula 1100 is in use.

For example, the stop 1190 may be positioned so that when the nasalcannula 1100 is in use, the stop is designed to engage the columella ofthe user's nose and thereby prevent the nozzles 1126, 1131 from beinginserted into the user's nares. In various embodiments, the first andsecond nozzles 1126, 1131 are positioned on either side of the stop 1190so that when the nasal cannula 1100 is operatively in use, the eachnozzle 1126, 1131 will be spaced apart from a respective particular oneof the patient's nares and will be positioned to direct a focused flowof gas into that particular nare by, for example, being positioned sothat the outlet (and distal end) of each nozzle (first nozzle outlet1183 and second nozzle outlet 1184) is substantially in-line (e.g.,substantially co-axial) with, a corresponding one of the patient'snares. Similar to cannula 1000, cannula 1100 has elongate extensions1170, 1172 that have conduit inlets at the distal ends. Elongateextensions 1170, 1172 are in gaseous communication with conduits, suchas conduit 1123.

As may be understood from FIG. 12, in various embodiments, the nasalcannula 1200 may include only a single nozzle 1227. The nozzle 1227, invarious embodiments, has an oblong or substantially ellipticalcross-section. In these embodiments, the major axis of the ellipse runssubstantially parallel to the central axis of the base portion 1205 ofthe nasal cannula. In one embodiment, the nozzle 1227 is wide enough toallow air to flow into both of a user's nares when the nasal cannula isin use. For example, in various embodiments, the width of the nozzle1227 (e.g., a length defined by the major axis of the nozzle'selliptical cross section) may be approximately equal to (or greaterthan) the total width of the user's nares. In various embodiments, thecannula 1200 includes a first tubing inlet 1217 and a second tubinginlet 1222.

As may be understood from FIG. 14, when the nasal cannula is operativelyin use, a first lateral side 1430 of the nozzle 1429 is spaced apartfrom, and adjacent, a user's first nare, and a second lateral side 1431of the nozzle 1429 is spaced apart from, and adjacent, the user's secondnare. In this and other configurations, the nozzle 1429 is configured todirect a focused flow of gas simultaneously into each of the user'snares. In various embodiments, when the nozzle is of a certain width,for example, approximately equal to (or greater than) the total width ofthe user's nares, and other widths, the nozzle 1429 is sufficiently wideto prevent the nozzle 1429 from being inserted into a user's nare, thuspreventing sealing of the nasal cannula with the nare and/or issufficiently wide to act as a stopping feature to prevent the nozzle1429 from being inserted in the user's nares when the nasal cannula isin use. In various embodiments, first and second elongate extensions1470, 1472 are inserted into the patient's nares. In variousembodiments, the cannula has tubing 1427 which may have multipleconduits and may be positionable around the ear(s) of the user duringuse.

In various other embodiments, the cannula's single nozzle may have adifferent cross-section that is not oblong or elliptical. For example,the nozzle may have a substantially circular cross-section, with adiameter that is wide enough to allow air to flow into both of a user'snares when the cannula is in use, while simultaneously being wide enoughto prevent insertion into a single nare. In various other embodiments,the nasal cannula may have more than one nozzle, each having asubstantially oblong cross section and a width that prevents insertioninto each of a user's nares.

In various embodiments, one or more of the cannula's elongate extensionshas a diameter that is adapted to prevent sealing with the user's nares.For example, the elongate extension(s) may have a diameter that issubstantially narrower than a user's nares, so that sealing is avoided.In other embodiments, the elongate extension(s) may include featuressuch as grooves or recesses, as described above, to prevent sealing wheninserted into a user's nare(s).

Exemplary Use of the Cannula

To use a cannula according to a particular embodiment of the invention,a physician or technician may have a patient use the cannula for a briefperiod of time, while the physician or technician monitors informationreceived from the cannula's various sensors, or the information may berecorded for later analysis. The physician or technician may then usethis information to adjust the structure or operation of the cannulauntil the cannula's sensors indicate that the patient's upper airwayenvironment satisfies certain conditions.

Similarly, in various embodiments, the cannula's sensors may be used tomonitor conditions within the patient's upper airway over time. In aparticular embodiment, the cannula's sensors may be connected to acontrol system that will automatically alter or modify the flow oftherapeutic gas into the cannula if information from the sensorindicates undesirable conditions within the patient's upper airway. Infurther embodiments of the invention, the sensor is connected to acontrol system that issues an alarm if information from the cannula'ssensors indicates undesirable conditions within the patient's airway.

FIGS. 13 and 14 depict various embodiments of nasal cannulas being usedon a patient. As may be understood from FIG. 13, for example, a nasalcannula is used on a young or small infant for high flow therapy. Forexample, a nasal cannula similar to that shown in FIG. 10 can be used.In various embodiments, first and second elongate extensions 1370, 1372are inserted into the patient's nares, while corresponding first andsecond nozzles 1326, 1331 remain adjacent and external to the patient'snares. As may be appreciated, when the nasal cannula is in use, airflows into the patient's nares via the nozzles. FIG. 14 depicts oneembodiment of a nasal cannula in use on a patient. In one embodiment, anasal cannula such as that shown in FIG. 12 can be used. As may beunderstood from FIG. 14, a nasal cannula having a single nozzle 1429 canbe used, in which the nozzle is sized and shaped (e.g., is ellipticaland/or wider than a patient's nare) to prevent insertion into thepatient's nares. In various other embodiments, nasal cannula havingnasal insert type nozzles, as described throughout, can be used. Inthese embodiments, the nasal inserts are inserted into the user's nareswhile the cannula is in use. Nasal cannula according to embodiments ofthe invention can be used on a variety of patients.

High Flow Therapy Device

Now referring to FIGS. 15-17, a high flow therapy device 2000 is shown.High flow therapy device 2000 is configured for use with a non-sealingrespiratory interface, such as cannula 100, for example, to deliver gasto a patient. In various embodiments, high flow therapy device 2000 isable to heat, humidify, and/or oxygenate a gas prior to delivering thegas to a patient. Additionally, embodiments of high flow therapy device2000 are able to control and/or adjust the temperature of the gas, thehumidity of the gas, the amount of oxygen in the gas, the flow rate ofthe gas and/or the volume of the gas delivered to the patient.

High flow therapy device 2000 is shown in FIG. 15 including a housing2010, a humidity chamber 2020 (e.g., vapor generator), a user interface2030, a gas inlet port 2040 and a gas outlet port 2050. A microprocessor2060, an air inlet port 2070, a blower 2080, an oxygen inlet 2090 and aproportion valve 2100 are illustrated in FIG. 16. A non-sealingrespiratory interface (such as a nasal cannula illustrated in FIGS. 1-14(e.g., 100 or 1200 and hereinafter referred to as 100), is configured tomechanically cooperate with gas outlet port 2050 to supply a patientwith gas. The user interface 2030 includes a user display that isadapted to display data as a graph. The data can include, but is notlimited to, pressure, amount of oxygen in the gas, the flow rate of thegas and/or the volume of the gas delivered to the patient. Asillustrated in FIG. 15, the display of user interface 2030 can bepositioned at an angle relative to the housing 2010 and/or a top surfaceof the housing 2010.

A heating element 2110 is shown schematically in FIG. 17 (and is hiddenfrom view by humidity chamber 2020 in FIG. 15) is in electricalcommunication with microprocessor 2060 (which is included on printedcircuit board (“PCB”)), via wire 2112, for instance, and is capable ofheating a liquid (e.g., water) within humidity chamber 2020 to create agas. Non-sealing respiratory interface 100 is configured to deliverythis gas to a patient. Further, a sensor 2120 or transducer (shown inFIG. 20) is disposed in electrical communication with microprocessor2060 and is configured to measure pressure in the upper airway UA(including both the nasal cavity and the oral cavity) of a patient. Inan embodiment, a conduit 2130 extends between the upper airway of thepatient and sensor 2120 (FIG. 19, sensor 2120 is not explicitly shown inFIG. 19, but may be disposed adjacent microprocessor 2060). In anotherembodiment, sensor 2120 is disposed at least partially within the upperairway of the patient with a wire 2122 relaying signals tomicroprocessor 2060 (FIGS. 18 and 20).

In use, a liquid (e.g., water) is inserted into humidity chamber 2020through a chamber port 2022, for instance. Heating element 2110 heatsthe liquid to create a vapor or gas. This vapor heats and humidifies thegas entering humidity chamber 2020 through gas inlet port 2040. Theheated and humidified vapor flows through gas outlet port 2050 andthrough non-sealing respiratory interface 100.

In a disclosed embodiment, sensor 2120 collects data for the measurementof the patient's respiration rate, tidal volume and minute volume.Further, based on measurements taken by sensor 2120 and relayed tomicroprocessor 2060, microprocessor 2060 is able to adjust thetemperature of the gas, the humidity of the gas, the amount of oxygen ofthe gas, flow rate of the gas and/or the volume of the gas delivered tothe patient. For example, if the pressure at the patient's upper airwayis measured and determined to be too low (e.g., by a pre-programmedalgorithm embedded on microprocessor 2060 or from a setting inputted bya operator), microprocessor 2060 may, for example, adjust the speed ofblower 2080 and/or oxygen proportional valve 2100 so that sufficientpressure levels are maintained.

Additionally, sensor 2120 may be used to monitor respiratory rates, andmicroprocessor 2060 may signal alarms if the respiratory rate exceeds orfalls below a range determined by either microprocessor 2060 or set byan operator. For example, a high respiratory rate alarm may alert theoperator and may indicate that the patient requires a higher flow rateand/or higher oxygen flow.

With reference to FIG. 17, a pair of thermocouples 2200 and 2202 isillustrated, which detect the temperature entering and leaving a circuit2210 disposed between respiratory interface 100 and gas outlet port2050. Further, a second heating element 2114 (or heater) (e.g., a heatedwire) may be disposed adjacent air outlet port 2050 to further heat thegas. It is also envisioned that second heating element 2114 is disposedwithin circuit 2210. Thermocouples 2200 and 2202 are in communicationwith microprocessor 2060 and may be used to adjust the temperature ofheating element 2110 and second heating element 2114. A feedback loopmay be used to control the temperature of the delivered gas, as well asto control its humidity and to minimize rainout. FIG. 16 illustrates anembodiment of circuit 2210 including conduit 2130 co-axially disposedtherein, in accordance with an embodiment of the present disclosure.

Relating to the embodiment illustrated in FIG. 16, blower 2080 is usedto draw in ambient air from air inlet port 2070 and force it through anair flow tube 2140, through gas inlet port 2040, through humiditychamber 2020 and through gas outlet port 2050 towards non-sealingrespiratory interface 100. Blower 2080 is configured to provide apatient (e.g., an adult patient) with a gas flow rate of up to about 60liters per minute. In a particular embodiment, it is envisioned thatblower 2080 is configured to provide a patient with a gas flow rate ofup to about 40 liters per minute. Additionally, an air intake filter2072 (shown schematically in FIG. 17) may be provided adjacent air inletport 2070 to filter the ambient air being delivered to the patient. Itis envisioned that air intake filter 2072 is configured to reduce theamount of particulates (including dust, pollen, fungi (including yeast,mold, spores, etc.) bacteria, viruses, allergenic material and/orpathogens) received by blower 2080. Additionally, the use of blower 2080may obviate the need for utilization of compressed air, for instance. Itis also envisioned that a pressure sensor is disposed adjacent airintake filter 2072 (shown schematically in FIG. 17), which may becapable of determining when air intake filter 2072 should be replaced(e.g., it is dirty, it is allowing negative pressure, etc).

With continued reference to FIG. 16, oxygen inlet 2090 and is configuredto connect to an external source of oxygen (or other gas) (notexplicitly shown) to allow oxygen to pass through high flow therapydevice 2000 and mix with ambient air, for instance. Proportion valve2100, being in electrical communication with microprocessor 2060, isdisposed adjacent oxygen inlet 2090 and is configured to adjust theamount of oxygen that flows from oxygen inlet 2090 through an oxygenflow tube 2150. As shown in FIGS. 16 and 17, oxygen flowing throughoxygen flow tube 2150 mixes with ambient air (or filtered air) flowingthrough air flow tube 2140 in a mixing area 2155 prior to enteringhumidity chamber 2020.

In a disclosed embodiment, sensor 2120 measures both inspirationpressure and expiration pressure of the patient. In the embodimentillustrated in FIGS. 18 and 19, conduit 2130 delivers the pressuremeasurements to sensor 2120 (not explicitly shown in FIGS. 18 and 19),which may be disposed adjacent microprocessor 2060. In the embodimentillustrated in FIG. 20, sensor 2120 is position adjacent the patient'supper airway and includes wire 2122 to transmit the readings tomicroprocessor 2060.

In various instances, clinicians do not desire ambient air to enter apatient's upper airway. To determine if ambient air is entering apatient's upper airway (air entrainment), the inspiration and expirationpressure readings from within (or adjacent) the upper airway may becompared to ambient air pressure. That is, a patient may be inhaling gasat a faster rate than the rate of gas that high flow therapy device 2000is delivering to the patient. In such a circumstance (since respiratoryinterface 100 is non-sealing), in addition to breathing in the suppliedgas, the patient also inhales ambient air. Based on this information,microprocessor 2060 of high flow therapy device 2000 is able to adjustvarious flow parameters, such as increasing the flow rate, to minimizeor eliminate the entrainment of ambient air.

FIG. 21 illustrates an example of a screen shot, which may be displayedon a display portion of user interface 2030. The crest of the sine-likewave represents expiration pressure and the valley representsinspiration pressure. In this situation, ambient air entrainment intothe patient's upper airway is occurring as evidenced by the valley ofthe sine wave dipping below the zero-pressure line. Microprocessor 2060may be configured to automatically adjust an aspect (e.g., increasingthe flow rate) of the gas being supplied to the patient by high flowtherapy device 2000 to overcome the entrainment of ambient air. Further,microprocessor 2060 may convey the pressure readings to the operator whomay then input settings to adjust the flow rate to minimize entrainmentof ambient air or to maintain a level of pressure above the ambient airpressure. Further, lowering the flow rates during expiration may alsominimize oxygen flow through high flow therapy device 2000. Suchlowering of a flow rate may also minimize entry of oxygen into a closedenvironment, such as the patient room or the interior of an ambulance,where high levels of oxygen might be hazardous.

In a disclosed embodiment, conduit 2130 may be used as a gas analyzer,which may be configured to take various measurements (e.g., percent ofoxygen, percentage of carbon dioxide, pressure, temperature, etc.) ofair in or adjacent a patient's upper airway.

In another embodiment (not explicitly illustrated), a gas port may bedisposed adjacent housing 2010 to communicate with exterior of housing2010. It is envisioned that the gas port is configured to allow the useof external devices to measure various gas properties (e.g., percentoxygen and pressure). Additionally, the gas port may be used forexternal verification of gas values. Further, a communications port2300, shown in FIG. 16, may be included to facilitate connection with anexternal device, such as a computer, for additional analysis, forinstance. Further, communications port 2300 enables connection withanother device, enabling data to be monitored distantly, recorded and/orreprogrammed, for example.

A directional valve 2160 and/or a sample pump 2170 (schematically shownin FIG. 17) may also be included to facilitate sampling the gas foranalysis. More specifically, in a particular embodiment, sample pump2170 is capable of moving a quantity of gas towards the gas analyzer. Asshown schematically in FIG. 17, the gas sample can be taken from apatient's upper airway via conduit 2130 or from mixing area 2155 via asample line 2180 and a sample port 2182 (FIG. 16). Directional valve2160 may be controlled by microprocessor 2060 to direct a gas samplefrom either location (or a different location such as after the gas isheated). The gas analyzer can compare measurements of the gas sample(s)with predetermined measurements to ensure high flow therapy device 2000is working optimally. It is further envisioned that sample pump 2170 maybe configured to pump a gas or liquid towards the patient to provide thepatient with an additional gas, such as an anesthetic, for instanceand/or to clean or purge conduit 2130.

The present disclosure also relates to methods of supplying a patientwith gas. The method includes providing high flow therapy device 2000,as described above, for example, heating the gas, and delivering the gasto the patient. In this embodiment, high flow therapy device 2000includes microprocessor 2060, heating element 2110 disposed inelectrical communication with microprocessor 2060, non-sealingrespiratory interface 100 configured to deliver gas to the patient andsensor 2120 disposed in electrical communication with microprocessor2060 and configured to measure pressure in the upper airway of thepatient. The method of this embodiment may be used, for instance, toprovide a patient with respiratory assistance. Blower 2080 may also beincluded in high flow therapy device 2000 of this method. Blower 2080enables ambient air to enter high flow therapy device 2000 (e.g.,through filter 2072) and be supplied to the patient. In such anembodiment, high flow therapy device is portable, as it does not need anexternal source of compressed air, for example.

Another method of the present disclosure relates to minimizingrespiratory infections of a patient. In an embodiment of this method,high flow therapy device 2000 includes heating element 2110 andnon-sealing respiratory interface 100. Here, a patient may be providedwith heated and/or humidified air (e.g., at varying flow rates) to helpminimize respiratory infections of the patient. Further, such a methodmay be used in connection with certain filters 2072 to help preventpatients from obtaining various conditions associated with inhalingcontaminated air, such as in a hospital. Additionally, providingappropriately warmed and humidified respiratory gases optimizes themotion of the cilia that line the respiratory passages from the anteriorthird of the nose to the beginning of the respiratory bronchioles,further minimizing risk of infection. Further, supplemental oxygen mayadd to this effect. Microprocessor 2060 in connection with sensor 2120may also be included with high flow therapy device 2000 of this methodfor measuring and controlling various aspects of the gas being deliveredto the patient, for instance, as described above.

A further method of the present disclosure relates to another way ofsupplying a patient with gas. The present method includes providing highflow therapy device 2000 including heating element 2110, non-sealingrespiratory interface 100, blower 2080, air inlet port 2070 configuredto enable ambient air to flow towards blower 2080 and filter 2070disposed in mechanical cooperation with air inlet port 2070 andconfigured to remove pathogens from the ambient air. High flow therapydevice 2000 of this method may also include microprocessor 2060 andsensor 2120.

Another method of the present disclosure includes the use of high flowtherapy device 2000 to treat headaches, upper airway resistancesyndrome, obstructive sleep apnea, hypopnea and/or snoring. High flowtherapy device 2000 may be set to provide sufficient airway pressure tominimize the collapse of the upper airway during inspiration, especiallywhile the use is asleep. HFT may be more acceptable to children andother who may not tolerate traditional CPAP therapy, which requires asealing interface. Early treatment with HFT may prevent the progressionof mild upper airway resistance syndrome to more advanced conditionssuch as sleep apnea and its associated morbidity.

Another method of the present disclosure is the treatment of headachesusing HFT. In an embodiment of treating/preventing headaches, gas may bedelivered to patient at a temperature of between about 32.degree. C. andabout 40.degree. C. (temperature in the higher end of this range mayprovide a more rapid response) and having at least about 27 milligramsof water vapor per liter. More specifically, it is envisioned that a gashaving a water vapor content of between about 33 mg/liter and about 44mg/liter may be used. It is envisioned that the gas being delivered tothe patient includes moisture content that is similar to that of atypical exhaled breath. In an embodiment, the flow rates of this heatedand humidified air are sufficient to prevent/minimize entrainment ofambient air into the respired gas during inspiration, as discussedabove. The inclusion of an increased percentage of oxygen may also behelpful. Further, the gas may be delivered to the patient usingnon-sealing respiratory interface 100.

High flow therapy device 2000 used in these methods includes heatingelement 2110 and non-sealing respiratory interface 100. Microprocessor2060 and sensor 2120 may also be included in high flow therapy device2000 of this method. The inclusion of blower 2080, in accordance with adisclosed embodiment, enables high flow therapy device 2000 to beportable, as it does not need to be connected to an external source ofcompressed air or oxygen. Thus, high flow therapy device 2000 of thismethod is able to be used, relatively easily, in a person's home, adoctor's office, an ambulance, etc.

The present disclosure also relates to a method of deliveringrespiratory gas to a patient and includes monitoring the respiratoryphase of the patient. Monitoring of a patient's respiratory phase isenabled by taking measurements of pressure in a patient's upper airway.Additionally, respiratory phase may be determined by pressure withcircuit 2210 or by monitoring activity of the phrenic nerve. Real-timepressure measurements (see sine-like wave in FIG. 21, for example)enable real-time supplying of gas at different pressures to be deliveredto the patient, or variable pressure delivery. For example, gas at ahigher pressure may be delivered to the patient during inspiration andgas at a lower pressure may be delivered to the patient duringexpiration. This example may be useful when a patient is weak and hasdifficultly exhaling against an incoming gas at a high pressure. It isfurther envisioned that the pressure level of the gas being delivered toa patient is gradually increased (e.g., over several minutes) to improvepatient comfort, for instance.

With reference to FIGS. 22-24, mouthpiece 3000 is illustrated inaccordance with an embodiment of the present disclosure. As brieflydescribed above, mouthpiece 3000 is an example of a respiratoryinterface of the present disclosure. Mouthpiece 3000 (illustratedresembling a pacifier) may be used to detect upper airway pressure of apatient.

A first mouthpiece port 3010 may be used to measure pressure insidemouthpiece 3000 through open end 3012 of first port. First mouthpieceport 3010 may include an open-ended tube that communicates the pressurewith mouthpiece 3000 to sensor 2120 (not explicitly shown in FIGS.22-24) via first port conduit 2130 a. Sensor 2120 may also be positionedwithin mouthpiece 3000. It is envisioned that mouthpiece 3000 is atleast partially filled with a gas or liquid, e.g., water.

The pressure within mouthpiece 3000 may help evaluate, record orotherwise use the pressure data for determining the strength of suckingor feeding, for instance. The timing of the sucking motion and thedifferential pressures in the mouth may also be measured. The suckingpressure may be used to help determine the strength of the sucking andmay be used to evaluate the health of an infant, for instance. Themeasurement of oral-pharyngeal pressure may also give data for settingor adjusting respiratory support therapy for the patient. It isenvisioned that a relatively short first mouthpiece port 3010 may beused so that a bulb 3030 of mouthpiece 3000 acts as a pressure balloon.It is also envisioned that a relatively long first mouthpiece port 3010having rigidity may be used to help prevent closure of the tube frompressure from alveolar ridges or from teeth, for example.

A second mouthpiece port 3020 is configured to enter a patient's mouthor oral cavity when mouthpiece 3000 is in use and is configured tomeasure pressure within the oral cavity (upper airway pressure) throughan open end 3022 of second mouthpiece port 3020. Pressure from withinthe upper airway (e.g., measured adjacent the pharynx) may betransmitted to sensor 2120 via second port conduit 2130 b or sensor 2120may be positioned adjacent mouthpiece 3000. That is, the pressurecommunicated from with the upper airway to the patient's mouth is thepressure being measured. It is envisioned that second mouthpiece port3020 extends beyond a tip of bulb 3030 to facilitate the acquisition ofan accurate upper airway pressure measurement.

Referring to FIG. 23, a balloon 3040 is shown adjacent a distal end 3024of second port 3020. Here, it is envisioned that a lumen of conduit 2130b is in fluid communication with the internal area of balloon 3040.Further, any forces against a wall of balloon 3040 are transmittedthrough the lumen towards sensor 2120 or transducer for control,observation or analysis.

The pressure within the oral cavity may vary during the phases ofsucking and swallowing. High flow therapy device 2000 using mouthpiece3000 enables concurrent measurement of sucking pressure withinmouthpiece 3000 and the pressure outside mouthpiece 3000. This data mayhelp determine treatment characteristics for respiratory support forinfants, children or adults, e.g., unconscious adults.

CONCLUSION

Many modifications and other embodiments of the inventions set forthherein will come to mind to one skilled in the art to which theseinventions pertain having the benefit of the teachings presented in theforegoing descriptions and the associated drawings. Therefore, it is tobe understood that the inventions are not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims. Forexample, although the embodiment shown in FIG. 1 shows each nozzle 125,130 having a two conduit inlets 152, 154, in alternative embodiments ofthe invention, one or more of the nozzles 125, 130 may have more or lessthan two conduit inlets (and/or more or less than two sensors). Further,sensor 2120 may be situated or in communication with any area of theairway, and is not limited to sensing the environment of the anteriornares. Although specific terms are employed herein, they are used in ageneric and descriptive sense only and not for purposes of limitation.

We claim:
 1. A high flow therapy system for delivering heated andhumidified respiratory gas to an airway of a patient, the systemcomprising: a respiratory gas flow pathway for delivering therespiratory gas to the airway of the patient by way of a non-sealingrespiratory interface; wherein flow rate of the respiratory gas iscontrolled by a microprocessor; a mixing area for mixing a first gas anda second gas in the respiratory gas flow pathway; a humidification areafor downstream of the mixing area and configured for humidifyingrespiratory gas in the respiratory gas flow pathway; and, a heateddelivery conduit for minimizing condensation of humidified respiratorygas.
 2. The high flow therapy system of claim 1, wherein at least one ofrespiration rate, tidal volume and minute volume are calculated by themicroprocessor.
 3. The high flow therapy system of claim 1, wherein themicroprocessor is configured to control at least one of the temperatureof the gas, the humidity of the gas, the mixture of the gas, the flowrate of the gas, and the volume of the gas delivered to the patient. 4.The high flow therapy system of claim 1, wherein the microprocessor isconfigured to adjust flow rates based on at least one of apre-programmed algorithm and a setting inputted by an operator.
 5. Thehigh flow therapy system of claim 1, wherein the system is configured tosignal an alarm when conditions deviate from pre-determined criteria. 6.The high flow therapy system of claim 1, wherein the system isconfigured to control the flow rate of the respiratory gas delivered tothe patient based on the respiratory phase of the patient during use. 7.The high flow therapy system of claim 1, wherein the system isconfigured to deliver the respiratory gas to the patient at differentairway pressures based on the respiratory phase of the patient duringuse.
 8. The high flow therapy system of claim 1, further comprising agas analyzer.
 9. The high flow therapy system of claim 1, furthercomprising a display.
 10. The high flow therapy system of claim 1,further comprising a proportional valve.
 11. The high flow therapysystem of claim 1, wherein the non-sealing respiratory interfaceincludes a nasal cannula.
 12. The high flow therapy system of claim 1,further comprising a blower.
 13. The high flow therapy system of claim1, further comprising a gas inlet configured to connect to an externalsource of gas.
 14. The high flow therapy system of claim 1, wherein theblower is configured for providing a patient with gas flow rates of upto 60 liters per minute.
 15. The high flow therapy system of claim 1,further comprising a sensing element for monitoring the airway of thepatient.
 16. The high flow therapy system of claim 15, wherein thesensing element communicates the monitored information to the high flowtherapy system.
 17. The high flow therapy system of claim 15, whereinthe sensing element is configured to measure at least one of inspirationpressure and expiration pressure of the patient.
 18. The high flowtherapy system of claim 15, wherein the sensing element is at leastpartially enclosed within the respiratory gas flow pathway.
 19. A highflow therapy system for delivering heated and humidified respiratory gasto an airway of a patient, the system comprising: a respiratory gas flowpathway for delivering the respiratory gas to the airway of the patientby way of a non-sealing respiratory interface; wherein flow rate of therespiratory gas is controlled by a microprocessor; a blower controlledby the microprocessor; a mixing area for mixing a first gas and a secondgas in the respiratory gas flow pathway; a humidification areadownstream of the mixing area and for humidifying respiratory gas in therespiratory gas flow pathway; and a heated delivery conduit forminimizing condensation of humidified respiratory gas.
 20. A high flowtherapy system for delivering heated and humidified respiratory gas toan airway of a patient, the system comprising: a respiratory gas flowpathway for delivering the respiratory gas to the airway of the patientby way of a non-sealing respiratory interface; wherein flow rate of therespiratory gas is controlled by a microprocessor located within ahousing; a mixing area located within the housing for mixing a first gasand a second gas in the respiratory gas flow pathway; a humidificationarea downstream of the mixing area and located outside of the housingfor humidifying respiratory gas in the respiratory gas flow pathway; aheating element coupled with the humidification area; and a heateddelivery conduit for minimizing condensation of humidified respiratorygas.